The Department of Health collected two different samples off Waikiki Wednesday and determined the substance seen floating in the water appears to be Trichodesmium, a type of cyanobacteria, also referred to as sea dust.
Another sample turned out to be debris. None of the samples contained petroleum, meaning they are not tar balls.
U.S. Coast Guard pollution investigators were called out to Waikiki Wednesday morning to look into reports of a mysterious substance in the water near the Duke Kahanamoku statue. They later turned the investigation over to the state.
A surfer said the substance looked like grease and it covered his board and leash. Nobody was told to stay out of the water.
According to the CDC, cyanobacteria are single-celled organisms that can multiply quickly, creating blooms that spread across the water’s surface. The blooms most often form in late summer or early fall. The DOH says it has not received any reports of reactions to the algae.
The state says this past Sunday during the Molokai to Oahu paddling race, a brown discoloration band was reported and first seen outside the Hawaii Kai channel. On Monday and Tuesday, the same band was then reported offshore Waikiki. The band is now about 10 -15 feet offshore. The material in the water appears to be from an algae bloom which is a natural biological occurrence.